Nice experiment. thank you for posting, but I think theoretically, this is a mess.
re the actual experiment - near the end he says:
"Time is physical as soon as there is one massive particle, but it definitely is something that doesn’t require more than one massive particle for
its existence. We know that a massless particle, like a photon, is not sufficient.”
Earlier he says:
"In the lab, Müller showed that he could measure this difference by allowing the matter waves of the fixed and moving cesium atoms to interfere in
an atom interferometer. The motion was caused by bouncing photons from a laser off the cesium atoms"
Given that the laser photons were required to put the atoms in motion, surely one of the main proofs here is that a measurement of time requires *at
least* the motions imparted by a photon? But he claims to have proven that 'massless' photons alone are not sufficient? I don't see it. Why
can't I count photon-photon interactions to make a photon clock? There is certainly a lot of science done on photon-photon collisions.
As for the theoretical assumptions in the article regarding time:
Every measurement of time requires an initial fixed length to measure against. Time is a second measurement of distance. In this experiment, he's
used the difference between the frequency his atoms to set his distance, then he is counting off that. It's funny that he mentions pendulums but
apparently fails to see that even a pendulum requires a fixed rod length to be set initially. It is this fixing of a countable unit, then the process
of counting which creates mathematically definable time. That's all time is. It certainly is not a ubiquitous physical dimension which hides away in
the quantum realm handing out timestamps.
Some physicists are actually waking up to this mathematically and operationally grounded definition of time:
"Scientists suggest spacetime has no time dimension"
"The concept of time as a way to measure the duration of events is not only deeply intuitive, it also plays an important role in our mathematical
descriptions of physical systems. For instance, we define an object’s speed as its displacement per a given time. But some researchers theorize that
this Newtonian idea of time as an absolute quantity that flows on its own, along with the idea that time is the fourth dimension of spacetime, are
incorrect. They propose to replace these concepts of time with a view that corresponds more accurately to the physical world: time as a measure of the
numerical order of change.
They begin by explaining how we usually assume that time is an absolute physical quantity that plays the role of the independent variable (time, t, is
often the x-axis on graphs that show the evolution of a physical system). But, as they note, we never really measure t. What we do measure is an
object’s frequency, speed, etc. In other words, what experimentally exists are the motion of an object and the tick of a clock, and we compare the
object’s motion to the tick of a clock to measure the object’s frequency, speed, etc. By itself, t has only a mathematical value, and no primary
physical existence. This view doesn’t mean that time does not exist, but that time has more to do with space than with the idea of an absolute time.
So while 4D spacetime is usually considered to consist of three dimensions of space and one dimension of time, the researchers’ view suggests that
it’s more correct to imagine spacetime as four dimensions of space. In other words, as they say, the universe is “timeless.”"